1. Field of the Invention
The present invention relates to an inverted microscope for magnifying and observing an observation sample laid on a stage by an objective lens disposed right under the sample.
2. Description of the Background Art
An inverted microscope has broadly been used in fields such as:
(1) Researches of respective fields of medicine and physiology in which living cells are handled; and
(2) Industrial researches/inspections for observing tissues and detecting defects and contents of various metal materials.
In recent years, cases to require functions other than a simple observation and photography have increased in researches and inspections in which the inverted microscope is used. Concretely, in addition to the visual observation and photography of a sample by an eyepiece, there are applications as follows. Examples of the applications include: using a TV camera to photograph the sample; observing a change of the sample with an elapse of time and performing an image processing; irradiating the sample with a laser beam and observing the change of the sample; and the like. Moreover, in the industrial researches and inspections for handling the metal materials, the examples of the applications also include: assembling a macro observation apparatus for observing the sample in a broader field of view with a low magnification; and combining an infrared ray and an imaging device for the infrared ray to observe an internal structure of the sample, not the surface of the sample.
For a purpose of increasing photography light paths which have an equal projection magnification, the following inverted microscope is known. The light successively transmitted through an objective lens and tube lens is split into photography light paths of three or more directions different from one another (see Jpn. Pat. Appln. KOKAI Publication No. 7-35986).
According to the above-described inverted microscope, three or more photography apparatuses such as a still camera and TV camera can be mounted. Moreover, the image magnifications of the sample images formed on the respective photography light paths by the tube lens can be set to be equal. Therefore, it is possible to easily compare and collate the respective images.
Additionally, in the inverted microscope, the light successively passed through the objective lens and tube lens is split into the photography light paths of three or more different directions. Therefore, the inverted microscope has to constantly include a first optical device in a microscope main body, and a so-called light path switch mechanism in which the position of the first optical device on the light path is switched and supply states of the light into the respective photography light paths are set to be variable.
Therefore, it is useless for a user who needs no photography light path to constantly include the first optical device and the light path switch mechanism for switching the first optical device, and this is a factor of cost increase of the microscope main body. Moreover, when TV observation is to be performed using an infrared ray in the industrial research/inspection, the tube lens and first optical device in the microscope main body have to be changed to types for transmission of the infrared ray by changing coatings in many cases. For this change, the inverted microscope needs to be transported to a manufacturing factory from the user, and further disassembling, modifying, and assembling operations of the inverted microscope are required. Therefore, a problem occurs that much labor and time are required for changing the types.
Moreover, the following inverted microscope is also known. A stage support member is expanded/contracted with respect to a microscope base, or a spacer member is disposed between at least one of the stage and microscope base and the stage support member, and thereby an optical system can newly be added to a structure (see Jpn. Pat. Appln. KOKAI Publication No. 11-72715).
According to the inverted microscope, a new space is formed between the stage and the microscope base. Moreover, the new optical system can be added and is disposed in the space. Furthermore, when the new optical system is disposed in a parallel flux emitted from the objective lens between the objective lens disposed under the stage and the tube lens disposed on the microscope base, optical capabilities of the microscope can substantially be prevented from being deteriorated.
When the stage support member is expanded/contracted and the spacer member is disposed as described above, a height of the stage from a base upper surface changes. Therefore, there are problems as follows.
(1) Operability of a stage handle for moving the stage in a horizontal plane and changing an observation portion of the sample is deteriorated.
(2) The heights of peripheral apparatuses such as a manipulator for use together with the inverted microscope from the base upper surface also need to be changed.
(3) The operation of removing the stage and stage support member, adding the new optical system, disposing the spacer member and assembling the stage and stage support member again is troublesome.
(4) The disposed spacer member deteriorates a degree to which the optical axis of the objective lens crosses at right angles to the stage surface, and optical capabilities are deteriorated.
Moreover, in the inverted microscopes including a filter block disposed below the stage of the microscope main body and a lighting projection unit for projecting an incident light illumination light onto the sample via the filter block, the inverted microscope including light receiving means for receiving the light from the sample instead of the lighting projection unit is also known (see Jpn. Pat. Appln. KOKAI Publication No. 11-194277).
According to the inverted microscope, when the light receiving means is mounted instead of the lighting projection unit, the light from the sample reflected by the filter block is received by the light receiving means, and converted to an electric signal. Therefore, even with a popular inverted microscope which has no image output port, it is possible to easily observe the microscope image and to detect the light amount.
However, the lighting projection unit is detached from the inverted microscope, and therefore a problem occurs that the microscope cannot be applied to the industrial researches/inspections such as the tissue observation of the metal materials requiring incident light illumination.
An object of the present invention is to provide an inverted microscope in which various auxiliary apparatuses applicable to the inverted microscope including incident light illumination for industrial use can easily be assembled, and which is inexpensive and superior in operability.
According to an aspect of the present invention, there is provided an inverted microscope comprising: an objective lens disposed under a sample; a tube lens which is disposed in a light path of an observation light emitted from the objective lens and which forms the observation light into an image; an incident light illumination optical device which is disposed between the objective lens and the tube lens, and which introduces incident light illumination into the light path of the observation light; and an input/output port which is disposed between the incident light illumination optical device and the tube lens, and which splits a light flux from the light path of the observation light or introduces the light flux into the light path of the observation light.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.